var citys=[{spell:"tianmen",city:"天门"},{spell:"tianxia",city:"天下"},{spell:"tiantang",city:"天堂"},{spell:"xiamen",city:"厦门"}]
var choose=[];
citys.forEach(item=>{
    if(item.spell.startsWith("tian")||item.city.startsWith("天")){
        choose.push(item.city)
    }

})
console.log(choose)